<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <!--1 直接拼接：语法过于繁琐-->
      <h2>{{firstName}} {{lastName}}</h2>
      <!-- 2 通过定义methods -->
      <!-- <h2>{{getFullName()}}</h2>
      <h2>{{getFullName()}}</h2>
      <h2>{{getFullName()}}</h2>
      <h2>{{getFullName()}}</h2>
      <h2>{{getFullName()}}</h2>
      <h2>{{getFullName()}}</h2> -->
      <!-- 3 计算属性 -->
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
      <h2>{{fullName}}</h2>
    </div>

    <script src="../js/vue.js"></script>

    <script>
      const app = new Vue({
        el: "#app",
        data: {
          firstName: "kobe",
          lastName: "Bryant",
        },
        methods: {
          getFullName: function () {
            // console.log("getFullName");
            // 会打印四次
            return this.firstName + " " + this.lastName;
          },
        },
        computed: {
          fullName: function () {
            // console.log("computed");
            // 只会打印一次
            // 只要监听的值不变，只会调用缓存
            return this.firstName + " " + this.lastName;
          },
        },
      });
    </script>
  </body>
</html>
